In the field of semi-automatic firearm designs various firing mechanisms exist which include both manual and automatic safety systems that function to reduce the possibility of inadvertently discharging a chambered cartridge.
Existing designs are complex and expensive to manufacture. For example: the devices disclosed in U.S. Pat. Nos. 4,282,795 to Beretta; 4,555,861 to Khoury; 4,021,955 to Curtis; 3,724,113 to Ludwig; and 4,590,697 to Ruger are hammer fired, therefore requiring complex parts which are costly to produce.
Many existing safety systems reduce the combat readiness of the firearm, and conversely, to increase the combat readiness one must compromise the protection provided by the safety systems. For example: the Beretta, Ludwig, and Ruger patents are designed to be carried with the hammer uncocked, relying on a double action mechanism to discharge the first shot. As such they are unable to deliver a first shot as accurately and quickly as a single action design can. If one were to carry these pistols in the cocked, or single action condition, safety would be compromised.
U.S. Pat. No. 4,539,889 to Glock discloses a striker fired mechanism with fewer parts, but requires a trigger pull similar to a double action mechanism for every shot.
Firing pin blocking safety systems are well known and are incorporated in pistols currently manufactured. However, the existing mechanisms incorporating these safety systems do not provide enough protection in the known areas of inadvertent discharge. For example, in the event of a sear failure: the Glock and Khoury patents are able to approach the battery position in a fail-unsafe condition; the Ludwig and Curtis patents may approach battery fail-unsafe if there is an imbalance of spring pressures within their mechanisms.
Currently manufactured pistols based on the Glock and Ludwig patents are without a manual safety, and as such may be discharged by any form of inadvertent trigger pull.
In view of the above, a need exists for a novel firearm design which has: a simple firing mechanism which is inexpensive to manufacture; multiple safety systems which prevent as many of the known types of inadvertent discharge as possible; and superior combat readiness without compromising safety features.